===================================================================
@@ -11754,7 +11754,8 @@
(zero_extend (match_dup 1)))]
"(peep2_reg_dead_p (3, operands[1])
|| operands_match_p (operands[1], operands[3]))
- && ! reg_overlap_mentioned_p (operands[3], operands[0])"
+ && ! reg_overlap_mentioned_p (operands[3], operands[0])
+ && peep2_regno_dead_p (0, FLAGS_REG)"
[(set (match_dup 4) (match_dup 0))
(set (strict_low_part (match_dup 5))
(match_dup 2))]
@@ -11775,7 +11776,8 @@
"(peep2_reg_dead_p (3, operands[1])
|| operands_match_p (operands[1], operands[3]))
&& ! reg_overlap_mentioned_p (operands[3], operands[0])
- && ! reg_set_p (operands[3], operands[4])"
+ && ! reg_set_p (operands[3], operands[4])
+ && peep2_regno_dead_p (0, FLAGS_REG)"
[(parallel [(set (match_dup 5) (match_dup 0))
(match_dup 4)])
(set (strict_low_part (match_dup 6))
@@ -11797,7 +11799,8 @@
(and:SI (match_dup 3) (const_int 255)))
(clobber (reg:CC FLAGS_REG))])]
"REGNO (operands[1]) == REGNO (operands[3])
- && ! reg_overlap_mentioned_p (operands[3], operands[0])"
+ && ! reg_overlap_mentioned_p (operands[3], operands[0])
+ && peep2_regno_dead_p (0, FLAGS_REG)"
[(set (match_dup 4) (match_dup 0))
(set (strict_low_part (match_dup 5))
(match_dup 2))]
@@ -11819,7 +11822,8 @@
"(peep2_reg_dead_p (3, operands[1])
|| operands_match_p (operands[1], operands[3]))
&& ! reg_overlap_mentioned_p (operands[3], operands[0])
- && ! reg_set_p (operands[3], operands[4])"
+ && ! reg_set_p (operands[3], operands[4])
+ && peep2_regno_dead_p (0, FLAGS_REG)"
[(parallel [(set (match_dup 5) (match_dup 0))
(match_dup 4)])
(set (strict_low_part (match_dup 6))
===================================================================
@@ -0,0 +1,30 @@
+/* PR target/81300 */
+/* { dg-do run { target { ! ia32 } } } */
+/* { dg-options "-O2" } */
+
+int
+__attribute__((noinline, noclone))
+foo (void)
+{
+ unsigned long long _discard = 0, zero = 0, maxull = 0;
+ unsigned char zero1 = __builtin_ia32_addcarryx_u64 (0, 0, 0, &_discard);
+ unsigned char zero2 = __builtin_ia32_addcarryx_u64 (zero1, 0, 0, &zero);
+ __builtin_ia32_sbb_u64 (0x0, 2, -1, &_discard);
+ unsigned char one = __builtin_ia32_sbb_u64 (0, zero, 1, &maxull);
+ unsigned long long x = __builtin_ia32_sbb_u64 (one, zero2, 0, &_discard);
+
+ unsigned long long z1 = 0;
+ __asm__ ("mov{q}\t{%1, %0|%0, %1}" : "+r" (z1) : "r" (x));
+ unsigned long long z2 = 3;
+ __asm__ ("mov{q}\t{%1, %0|%0, %1}" : "+r" (z2) : "r" (x));
+
+ return 1 - (z1 | z2);
+}
+
+int main ()
+{
+ if (foo ())
+ __builtin_abort ();
+
+ return 0;
+}
Hello! Attached patch tightens peephole2 condition to prevent unwanted flags_reg clobbering by insn patterns, emitted by ix86_expand_clear. 2017-07-04 Uros Bizjak <ubizjak@gmail.com> PR target/81300 * config/i386/i386.md (setcc + movzbl/and to xor + setcc peepholes): Require dead FLAGS_REG at the beginning of a peephole. testsuite/ChangeLog: 2017-07-04 Uros Bizjak <ubizjak@gmail.com> PR target/81300 * gcc.target/i386/pr81300.c: New test. Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}. Committed to mainline, will be backported to release branches. Uros.